The benefit comes at high rpm. The engine driven pump load goes up as rpm goes up but an electric is constant speed/load. 5000 rpm very possible to see a 20hp benefit. Although that is a drop in the bucket as to what the disco needs to feel quicker. Needs about another 150 ft lbs of torque.

 

I'm curious on the cost to improved horsepower ratio. Or engine efficiency, since reducing the load on the engine should require less fuel. I don't think a fan in this case will improve it, but going off the idea of a water pump. Or Mntnceguy's other thread on a power steering pump alternative.

I'm always looking to make the D2 more fuel efficient, but the cost of the modifications must pay itself off in gas within 1-2 years for me. Being in California gas is $$$ so the payoff would be greater. I'd estimate I spend ~$5,200 on gas a year. My driving is very inconsistent but averaging it out to about $100 on gas a week x 52 weeks in a year. Very rough estimate. Assuming a generous 5-10% improvement to mpg, that could be nearly $210-$520 dollars a year in my case. I should make a new thread asking how much people spend on gas a year for these rigs...

 

I had a 260k mile truck that got 17 consistently at 70mph. Electric fans improve about 1 mpg, they almost never run at highway speeds. If you want to hypermile, get some Michelin tires in stock size, usually good for 1 mpg. Electric WP and PS would not likely benefit much in terms of MPG, MPG usually occurs around 2000-2500 rpm and HP is around 4500 rpm.

 

As much as I would love to drive the D2 on stock tires, its the off-road build/DD. I've got at least 600-800lbs of extra weight between the steel bumpers, sliders, roof rack, steel rims, 32" tires, gear stored inside, etc. I'm running a 3" suspension and 1" body lift, and a rather tall safety roof rack. Only way I could drop my mpg at this point is if I add a sail on top. The only plausible way to improve mpg in my case is through engine efficiency, getting rid of small bits and piece for weight, and changing driving habits. The latter 2 I'm currently working on.

Idk my mpg, as I either drive short distances (less than 15 miles), with hills (up and down 400 ft) or long road trips followed by off-roading. I tend to drive in the right land doing 55-65, trying to keep it in 4th gear at around @2500 rpm. I've rarely ever floored it in the D2 to reach the high hp. The highest RPM I've seen is around 4,000. I've probably gone higher when merging on the highway in dicey situations but I'm looking elsewhere in those situations.

A while back I was looking at buying another set of rims + tires for daily driving but the cost of the tires wouldn't make up for it. I off-road or camp around every 3-4 weeks so I would be constantly swapping tires. Plus the long distance trips is where I would see the best results but 90% of time they are wheeling trips. Which bringing 4 extra rims and tires is a huge waste of space and weight.

 

Just wrapped up installation of a Fusion fan using a Derale PWM controller and I'm very happy with the results and products used.

 

That's some nice fab work on those mounting brackets, they look really fantastic! Nicely done for sure!

I'm interested in seeing how the radiator side tanks react to the fans being mounted to them. They may be just fine, but there may also be a chance that it'll cause them to eventually leak with the added weight and vibration. I mounted my fans to the core support and cross member with that issue in mind, just in case. So, I'm glad to see you mounted it to the radiator so we can see if that effects the system at all. Please report back with any issues in the future, and Thank you!

As a side note, now that you have the E-fans installed, you can also rotate the inline thermostat engine side outlet hose 90 degrees away from the alternator pulley so it can't rub thru on accident. Just shorten the upper radiator hose to fit, easy peasy

Again, nice work man!

Happy Modding!

 

Saw this lil video today about how much power is robbed with a clutch style fan vs an E-fan, and at different RPM's, done with multiple dyno pulls on two different vehicles. Thought it might be nice to see some actual numbers for those folks whose butt dynos don't work, or are just your run of the mill doubting types....


At a ballpark estimate of about 7% to 12% power gain as this videos findings show, the Disco would free up about 17-26HP with an E-fan in the mid to high RPM range. That's not nuthin in my book, and should definitely be able to be felt by those who have functioning backsides.....